Method of distilling hydrocarbons



N Zmn MWQQ Jan. 3, 1928.

.- w. M. DUNCAN METHOD OF DISTILLING HYDROCARBONS,

Filed July 14. 1924 Patented Jan. 3, 1928.

UNITED STATES WILLIAM M. DUNCAN, OF ALTON, ILLINOIS.

METHOD OF DISTILLING HYDROCARBON S.

Application filed July 14, 1924. Serial No. 725,840.

This invention relates to methods of distilling hydrocarbons, one of the objects being to distill liquid and solid hydrocarbons at the same time, and to accomplish this in an economical manner by transmitting heat from the liquid to the solid material. Another object is to avoid overheating of the solid material so as to minimize the production of permanent gas and obtain the volatile fractions in a liquid state. A further object is to produce a novel volatile liquid product consisting of a new mixture of low boiling point fractions obtained partly from a liquid hydrocarbon and partly from solid hydrocarbon material.

To set forth one form of the invention I will hereafter describe a method including the steps of distilling a hydrocarbon liquid, for example a petroleum oil and transmlttmg heat from the liquid to a body of solid hydrocarbon material, such as coal, shale, or the like. Both bodies are maintained at temperatures high enough to vaporize their volatile constituents, and the vapors may be condensed in any suitable manner. If desired the vapors may be commingled with each other and condensed to form a liquid consisting of the volatile fractions of the different hydrocarbons.

In the preferred form of the invention, the charge of liquid hydrocarbons is heated by a suitable fire, and heat is trans mitted from the liquid to the solid hydro carbons. A charge of the solid hydrocarbons may be submerged in the liquid and a charge of the same material may be arrangedin the vapor line. By transmitting the heat in this manner, I can avoid overheating of the solid material and distill the volatile fractions therefrom without producing excessive amounts of permanent gas.

In addition to avoiding overheating of the solid material and thereby recovering its volatile fractions in a liquid state, the present invention preferably includes the advantage of utilizing hydrocarbon vapors as a means for heating and vaporizing the volatile fractions of the solid material. The vapors passing from the fire-heated liquid are preferably transmitted through a mass of the solid hydrocarbon material and then to a condenser. Since the system must include a means for cooling the vapors, it is highly economical to transmit heat from the vapors to a charge of solid hydrocarbon material, for this does not materially increase the cost of distilling the hydrocarbon liquid, and it results in a second distilling operat1on, wherein the solid hydrocarbons are heated to ten'iperatures high enough to remove their volatile fractions.

Assuming that the liquid to be distilled 1s a petroleum oil and that the solid hydrocarbonsare lumps of bituminous coal arranged m the vapor line between the liquid charge and the condenser, the highly heated vapors will pass through the mass of bituminous coal and remove the volatile fractions therefrom. A part of the coal is thus converted into a valuable volatile liquid, and instead of destroying the coal this operation improves it by removing its smoke-producing fractions.

With the foregoing and other objects in view, the invention comprises the particular method herein described and illustrated by the accompanying drawing, and it is to be understood that the invention comprehends variations and modifications within the scope of the claims hereunto appended.

The drawing is a diagrammatical View, partly in section, showing an apparatus embodying the features of this invention.

1 designates a still containing a body of hydrocarbon liquid 2 and arranged over a heating chamber 3 provided with a grate 4; for coal, or'other fuel. However, this is merely a diagrammatical illustration of a suitable means for vaporizing a hydrocarbon liquid. The vapors rising from the liquid pass through a pipe 5 and thence through various elements which will be hereafter described, the volatile fractions being conducted through a pipe 6 to a condenser 7. A grid8 may be arranged in the still to support a mass of coal 9, or the like.

The vapor line includes a pair of chambers 10 and 10 surrounded by heat-insulating material 11, branch pipes 12 and 12 leading from the pipe 5 to the lower ends of the respective chambers 10 and 10, pipes 13 and 13 connecting the upper ends of said chambers to a. pipe 14, a reflux condenser 15 at the upper end of pipe 14, and the vapor pipe 6 leading from the refiux condenser to the final condenser 7. A return pipe 16 leads from the reflux condenser 15 to the still 1.

Each of the chambers 10 and 10 is adapted to contain a' charge of bituminous coal 17, or other solid hydrocarbon material, preferably in the form of lumps, and each of said chambers has a closure 18 at the top adapted to be opened to admit the coal, and a closure 19 at the bottom where the residual coal is discharged. The closures may be secured by means of bolts 20. To prevent clogging of the vapor pipes 12 and 12, each chamber 10 and 10 is provided at the bottom with a grid 21 through which the vapors are admitted to the coal.

'Valves 22 and 22 are arranged in the vapor line as shown by the drawings, so the outgoing vapors can be diverted from one of the coal-chambers to the other. lVhen the chamber 10 is in service, the valves 22 are closed and the valves 22 are open. Vapors rising from the still then pass through the mass of coal in the chamber 10 to the reflux condenser 15, where the high boiling point fractions are condensed and conducted through pipe 16'to the still 1, while the low boiling point fractions pass to the condenser 7. In the apparatus shown by the drawing, the vapors derived from the liquid and solid materials are mixed with each other and transmitted to the reflux condenser, so the reflux condensate will usually contain some of the fractions derived from the coal and these fractions will be vaporized in the still 1.

After the desired fractions have been removed from the coal in chamber 10, the valves 22 are opened and the valves 22 are closed. The vapors are thus diverted to the charge in chamber 10 while the residual coal is removed from the chamber 10. A fresh charge of coal is then introduced into the chamber 10. It will thus be understood that the chambers 10 and 10' can be used alternately without stopping the distillation of the liquid in the still 1.

To prevent ignition of the vapors when they are diverted to a chamber containing a fresh charge of coal, the air may be expelled by means of steam, each chamber 10 and 10 being provided with a pipe 23 for the admission of steam and a pipe 24 through which air and steam are discharged. After a fresh charge is introduced into a chamber its top and bottom closures are tightly secured and steam is forced through the chamber to expel the air therefrom. The steam pipes 23 and 24: are provided with valves 25 which are operated to control the flow of steam through the chambers.

The present invention may be used in a cracking system wherein high temperatures and pressures are employed. For example, the liquid in the still 1 may be a high boiling point petroleum product, such as fuel oil, gas oil, or kerosene, maintained at a temperature higher than 600 F., for example 7 50 F., and the valve 26 in the vapor pipe 6 may be regulated to maintain a pressure higher than 50 lbs. per square inch in the still, coal chamber, and reflux condenser. A pressure of 90 lbs. per square inch would be satisfactory.

However, the present invention is not limited to the degrees of pressure and temperature herein mentioned, nor to any particular means for heating the hydrocarbon liquid.

Although the chambers 10 and 10 are preferably surrounded by heat-insulating material 11, the temperature of the vapors will be reduced therein, and the high boiling point condensate resulting from this cooling can be returned to the still through the pipes 12 or 12.

The system herein disclosed as the proferrcd form of the invention produces a new motor fuel containing the volatile constituents of hydrocarbon oil and-bituminous coal, and this fuel is obtained Without overheating the coal. Moreover, the coal is most economically distilled by heat derived from vapors passing from the heating zone to the condenser, and the cooling of the vapors is an essential of ordinary distillation, so the added step of distilling the coal is an aid to the operation of distilling the hydrocarbon liquid and does not increase the cost of the latter operation. Another important feature lies in the removal of the undesirable smoke-producing fractions from the coal and converting them into a valuable liquid.

1 claim:

1. The method which comprises distilling and cracking hydrocarbon 'liquid under a pressure greater than 50 pounds per square inch, transmitting the resultant vapors while under pressure through a chamber containing a charge of solid hydrocarbon material so as to vaporize the volatile constituents of said solid material, continuing this operation until the desired volatile fractions have been removed from said solid material, then continuing the distillation of said liquid and diverting the vapors from said chamber while still utilizing the heat of said vapors to distill another portion of said solid material, removing the solid material from the distilling system, introducing a fresh charge of solid hydrocarbon material into said chamber. expelling the air from said chamber, and then transmitting the vapors through said chamber.

2. The method which comprises distilling a. hydrocarbon liquid, transmitting the resultant vapors through a chamber containing a charge of solid hydrocarbon material so as to vaporize the volatile constituents of said solid material, continuing this operation until the desired volatile fractions have been removed from said solid material, thencontinuing the distillation of said liquid and diverting the vapors from said chamber while still utilizing the heat of said vapors to distill another portion of said solid material, removing the solid material from said chamber, introducing a fresh charge of solid hydrocarbon material into said chamber, expelling the air from said chamber, and then transmitting the vapors through said chamber.

3. The method which comprises distilling a hydrocarbon liquid, transmitting the resultant vapors through a chamber containing a mass of coal so as to vaporize the volatile constituents of said coal, continuing this operation until the desired volatile fractions have been removed from said coal, then continuing the distillation of said liquid and diverting the vapors from said chamber While still utilizing the heat of said vapors to distill another portion of said coal, removing the residual coal from'said chamber, introducing a fresh charge of coal into said chamber, forcing steam through said chamber to expel the air therefrom, and then transmitting the vapors through said chamber.

4. The method which comprises vaporizing and cracking a body of hydrocarbon liquid under pressure in a suitable still, transmit-v ting heat from the vapors While under pressure to a mass of solid hydrocarbon material located outside of said still and thereby vaporizing the volatile constituents of said material, at the same time cooling said vapors in said mass of solid material to condense the high boiling point fractions, returning the high boiling point condensate for further cracking Without admitting said solid-material to the interior of said still, and condens- WILLIAM M. DUNCAN. 

